Animal bites presenting to the emergency department: Spectrum, seasonal variation, and outcome

Abstract

Context: Animal bites including insect, reptile, and mammalian bites are common presentations to the emergency department (ED). Although profile and outcome of individual bites are described in detail, the literature on comprehensive overall clinical spectrum and seasonal variation of all animal bites is scant. Aims: To describe the spectrum, seasonal variation, clinical features, and outcomes of all patients presenting as emergencies due to animal bites. Methods: All the patients who presented to the ED of a large tertiary care hospital in South India with bites from January 2017 to December 2018 were retrospectively included in the analysis. Results: During the 2-year study period, animal bites constituted 0.83% of all ED admissions with 1145 incidents included in our analysis. The various animal bites/stings were classified as follows: mammal bites (480: 41.9%), arthropod bites (275: 24%), reptile bites (290: 25.3%), and unknown bites (100: 8.6%). We found an increase in the incidence of bites during the monsoon months of July to September (average: 58 cases per month) in our geographical locality. More than half (46: 58%) of scorpion stings had features of envenomation while a quarter (19: 24%) had the signs of autonomic storm. Snake bites constituted a quarter (25.2%: 289/1145) of all animal bites with 66% (191/289) showing features of envenomation. Dog bites constituted the majority of mammalian bites with 73% (352/480), followed by rat bites (14%: 68/480), cat bites (7.5%: 37/480), human bites (2.5%: 12/480), and monkey bites (1.9%: 9/480). The World Health Organization rabies exposure Category 3 bites were seen in 48%, 12%, and 27% of dog, rat, and cat bites, respectively. Conclusion: Snake and dog bites comprised the majority of all animal bites. There was a clear seasonal pattern with increased prevalence of bites during the rainy season.